Method and Apparatus for Temperature Characterization in Welding

ABSTRACT

An example system for controlling heating of a workpiece includes: an interface configured to receive a target temperature (TT) for the workpiece; a processor configured to: select a current temperature (TS) for the workpiece based on monitoring one or more temperature sensors; and set a control temperature (TC) based on the received target temperature and TS; and a control system configured to: control heating of the workpiece via a heating device until the workpiece reaches TC as measured by at least one of the one or more temperature sensors, and controlling the heating device to stop heating the workpiece in response to the workpiece reaching TC; wherein: the processor is configured to characterize a temperature ramp rate based on a measured temperature overshoot at the workpiece after turning off the heating device; and the control system is configured to control heating of the workpiece to TT by controlling the heating device based on the temperature ramp rate.

RELATED APPLICATIONS

This patent is a continuation-in-part of U.S. patent application Ser.No. 16/995,018, filed Aug. 17, 2020, entitled “Method and Apparatus forTemperature Characterization in Welding,” and claims priority to U.S.Provisional Patent Application Ser. No. 62/890,181, filed Aug. 22, 2019,entitled “Method and Apparatus for Temperature Characterization inWelding.” The entireties of U.S. patent application Ser. No. 16/995,018and U.S. Provisional Patent Application Ser. No. 62/890,181 areincorporated herein by reference.

BACKGROUND

The present disclosure relates to heating a workpiece for welding, andmore particularly, to a method and apparatus for temperaturecharacterization for optimally heating a workpiece for welding.

Induction heating is a method for producing heat in a localized area ona susceptible metallic object. Induction heating involves applying an ACelectric signal to a heating loop or coil placed near a specificlocation on or around the metallic object to be heated. The varying oralternating current in the loop creates a varying magnetic flux withinthe metal to be heated. Current is induced in the metal by the magneticflux, thus heating it. Induction heating may be used for many differentpurposes including curing adhesives, hardening of metals, brazing,soldering, and other fabrication processes in which heat is a necessaryor desirable agent.

Limitations and disadvantages of conventional systems for heating aworkpiece for welding will become apparent to one of skill in the art,through comparison of such approaches with some aspects of the presentmethod and system set forth in the remainder of this disclosure withreference to the drawings.

SUMMARY

Methods and systems are provided for temperature characterization inwelding, substantially as illustrated by and described in connectionwith at least one of the figures, as set forth more completely in theclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of some various aspects ofexamples of the disclosure, taken in conjunction with the accompanyingdrawings.

FIG. 1 is a high-level block diagram of an example heating system, inaccordance with aspects of the disclosure.

FIG. 2 shows a block diagram of an example control circuitry, inaccordance with aspects of the disclosure.

FIG. 3 shows a flow diagram representative of example machine readableinstructions, which may be executed by the example control circuitry ofFIGS. 1 and/or 2 to implement the example heating system of FIG. 1.

FIG. 4 shows a detailed flow diagram representative of example machinereadable instructions, which may be executed by the example controlcircuitry of FIGS. 1 and/or 2 to implement the example heating system ofFIG. 1.

FIG. 5 shows a flow diagram representative of example machine readableinstructions, which may be executed by the example control circuitry ofFIGS. 1 and/or 2 to implement the example heating system of FIG. 1.

The figures are not necessarily to scale. Where appropriate, similar oridentical reference numbers are used to refer to similar or identicalcomponents.

DETAILED DESCRIPTION

Various examples of the disclosure improve heating of a workpiece (e.g.,a workpiece to be welded, brazed, etc.) to a target temperature byimproving the accuracy of the heated workpiece temperature. For example,when working with smaller workpieces, a workpiece may be easilyoverheated by conventional heating systems because of the lower thermalmass of such workpieces. In some cases, overheating can damage theworkpiece and/or delay performance of the welding operation. Therefore,conventional methods to avoid overheating the workpiece involve anoperator closely attending to heating of the workpiece for welding,which may lead to inefficient use of time. When the workpiece is notsufficiently heated (e.g., is heated to less than the target temperatureto avoid overheating), extra time may be needed for the actual weldingprocess since the workpiece now needs additional time to be heated tothe required temperature. Insufficient heating may lead to greaterchances of failed weld, and may result in rejection of a weld doneaccording to a weld procedure specification (WPS).

Therefore, when using, for example, a thermostatically controlledinduction heating system to bring a workpiece to a desired temperature,users must be vigilant to ensure that undesired overheating does notoccur due to the improper placement or slow response of a temperaturesensing device. Monitoring can be particularly important when a heatingcapacity of a heating device, such as, for example, an induction heatingdevice, exceeds what is required to heat a given workpiece and resultsin very short heating times.

The situations described above can occur, for example, where users areheating a workpiece with a small thermal mass and/or while using atemperature sensing device that may be poorly thermally coupled to theworkpiece (e.g., armored temperature sensing device, temperature sensingdevice not tightly placed against the workpiece, etc.). However,overheating and/or poor thermal coupling may occur with workpieces ofany size.

In the disclosed examples, the user need not manually calculate and setpower limits to reduce the temperature overshoot when heating aworkpiece. By increasing the accuracy of heating the workpiece andreducing the overshoot of poorly thermally coupled temperature sensingdevices, the user can better make use of temperature sensing devicessuch as, for example, armored temperature sensing devices in varioussituations, which can result in quicker setup for the user. Disclosedexample systems and methods can also aid in reducing wear on heatingtools by limiting potential temperature overshoot past safe tooloperating limits.

FIG. 1 is a high-level block diagram of an example heating system, inaccordance with aspects of the disclosure. Referring to FIG. 1, there isshown an example heating system 100 that comprises a control circuitry105 configured to control a heating device 110 suitable for heating aworkpiece 130, and sensors 120 suitable for monitoring a temperature ofthe workpiece 130. The heating system 100 may use any type of a heatingsystem, and an example heating system may be an induction heatingsystem.

Accordingly, the example heating device 110 is described in thisdisclosure for the heating system 100. The heating device 110 comprisesinduction heating power supply 104, conductors 106, and a heating coil108. The heating system 100 is configured to provide power from theinduction heating power supply 104 to the heating coil 108 via theconductors 106. The heating coil 108 is magnetically coupled to theworkpiece 130 that is to be heated via the heating device 110. Inoperation, the induction heating power supply 104 outputs power to theheating device 110 at a heating frequency, which transfers the power tothe workpiece 130 to inductively heat the workpiece 130. The heatingpower supply 104 may be coupled to the heating device 110 via anextension cable.

The temperature of the workpiece 130 can be monitored at variouslocations by the sensors 120, which may comprise, for example,temperature sensors. The sensors 120 may be any type of sensors suitablefor monitoring the temperature of a welding workpiece, such as, forexample, armored temperature sensing devices or spot-welded sensingdevices.

The control circuitry 105 is configured to monitor and control variousfunctions. For example, the control circuitry 105 can monitortemperature information from the sensors 120 so that the heating device110 can be controlled to appropriately control the temperature of theworkpiece 130. The control circuitry 105 can also characterize, based onthe received inputs from the sensors 120 and a user via a user interface(e.g., input devices 242 in FIG. 2), a temperature ramp rate for aworkpiece so that it can be heated to the desired temperature withoutoverheating the workpiece.

The control circuitry 105 comprises a hardware device capable ofexecuting instructions to perform specific functions. Accordingly, thecontrol circuitry 105 comprises any of a number of different types ofprocessors, memory, logic circuitry, etc. for controlling the heatingdevice 110.

An example heating coil 108 may include two or more conductors and aturn connector. The conductors (and, by extension, the heating coil 108)may be conformably wrapped around the workpiece 130 while the conductorsare not electrically connected in series. The example heating coil 108may comprise, for example, an induction heating blanket, an inductionheating assembly, etc. The turn connector connects the two or moreconductors in series to configure the first and second conductors as aninductor having two or more turns. The example heating coil 108 mayinclude one or more electrical and/or thermal insulators to, forexample, prevent short circuiting and/or protect the conductors fromheat induced in the workpiece 130.

FIG. 2 shows a block diagram of an example control circuitry, inaccordance with aspects of the disclosure. Referring to FIG. 2, there isshown an example control circuitry 200 that may be used with variousexamples of the disclosure, and may be similar to the control circuitry105 in FIG. 1. The control circuitry 200 may comprise, for example, aprocessor 210, memory 220, a communication interface 230, and an IOinterface 240. The processor 210 may comprise, for example, one or moreof processors (CPUs, GPUs, etc.), controllers, system on chips, ASICs,etc.

The memory 220 may include non-volatile memory 226 and volatile memory228. The storage described for holding local data may be part of thememory 220 or comprise separate memory. The operating system 222 andapplications 224 may be stored in, for example, the non-volatile memory226, and may be copied to volatile memory 228 for execution by theprocessor 210. Various aspects of the disclosure may use differentmemory architectures that are design and/or implementation dependent.For example, some aspects of the disclosure may have the operatingsystem 222 and applications 224 in the non-volatile memory 226 executedat least in part from the non-volatile memory 226.

The communication interface 230 may allow the control circuitry 200 tocommunicate with other devices via, for example, a wired protocol suchas USB, Ethernet, Firewire, etc., or a wireless protocol such asBluetooth, Near Field Communication (NFC), Wi-Fi, etc. The wired orwireless protocol may also be, for example, a proprietary protocol. Thevarious types of radios for communication may be referred to as atransceiver for the sake of simplicity. The communication may be, forexample, with various sensors and/or devices that can relay sensor data.The communication interface 230 may also be used to communicate withother networks such as local networks, cellular networks, etc.Additionally, the communication interface may allow various devices toplug into, for example, a USB ports. For example, a keyboard and/or amouse may plug into their respective USB ports, or communicatewirelessly to a USB dongle that allows wireless communication with, forexample, a wireless keyboard and/or mouse.

The control circuitry 200 may also comprise the IO module 240 forcommunication with a user via the input devices 242 and outputinformation to be displayed on output devices 244. The input devices 242may comprise, for example, switches, slide switches, membrane switches,buttons, touch sensitive screen, which may be a part of a display, amicrophone, etc. The touch sensitive screen (touchscreen) may have softbuttons, switches, slide switches, keyboard, etc. that emulate theirphysical counterparts. The input devices 242 may also comprise, forexample, a keyboard, a mouse, a trackball, etc., as well as varioussensors, cameras, etc. The input devices 24 may additionally comprise,for example, bar code readers and/or other type of scanners that may beused to identify an object. The output devices 244 may comprise, forexample, display(s), speaker(s), LED(s), vibration motor(s), etc. Somedevices such as a touchscreen are able to provide both input and outputfunctions of the IO module 240.

The processor 210 may operate using different architectures in differentexamples of the disclosure. For example, the processor 210 may use thememory 220 to store instructions to execute, or the processor 210 mayhave its own memory (not shown) for its instructions.

Various examples may use other architectures where the differentfunctionalities may be grouped differently. For example, thefunctionalities may be in different integrated circuit chips, ordifferent devices may be combined. For example, the IO module 240 andthe communication interface 230 may be combined together. Additionally,the control circuitry 200 may refer logically to various physicaldevices. For example, one or more of the output devices 244 may be partof a different integrated circuit or on a different printed circuitboard than one or more of the input devices 242.

FIG. 3 shows a flow diagram representative of example machine readableinstructions 300, which may be executed by the example control circuitry105, 200 of FIGS. 1 and/or 2 to implement the example heating system 100of FIG. 1. For example, the instructions 300, which may be in anapplication 224, may be executed by the processor 210 to control theheating device 110 to heat a workpiece 130 to a target temperature. Aninduction heating device is used as an example for the heating device110, and it should be understood that various examples of the disclosuremay use any type of heating device appropriate for a purpose such as,for example, welding.

In block 302, a start request for heating is received. In block 304, theheating device 110, for example, an induction heating device, isenabled. In block 306, a target temperature T_(T) to which the workpiece130 should be heated is received. The target temperature may be, forexample, entered or selected by a user via the input devices 242 orreceived from another electronic device wirelessly and/or by wiredcommunication via the communication interface 230. The workpiece 130 mayalso recognized by scanning an identification mark such as, for example,a bar code, with an input device 242, optically recognized by anapplication 224, etc., and then the target temperature looked up in, forexample, a look-up table in the memory 220.

In block 308, the control circuitry 105 receives, wirelessly and/or viawire conductors, outputs from one or more sensors 120, each configuredto monitor a temperatures at a location of the workpiece 130. Thetemperature monitoring may occur continuously or at some time interval.When the target temperature T_(T) is received or determined, the controlcircuitry 105 will select the highest temperature T_(H) for theworkpiece 130 monitored via the sensors 120.

In block 310, the target temperature T_(T) is compared to the highesttemperature T_(H). Depending on the result of the comparison, thecontrol temperature T_(C) is set in block 312. FIG. 4 describes block312 in more detail.

In block 314, the heating device 110 heats the workpiece 130 to thecontrol temperature T_(C), or to substantially the control temperatureT_(C) as allowed by the heating system 100. “Substantially the controltemperature T_(C)” may be a temperature within a pre-determined marginto the temperature T_(C) that may be pre-determined for a given usage.The pre-determined margin may depend on various parameters, such as, forexample, the type of metal being heated, the type of heating device 110,etc. Accordingly, “substantially the control temperature T_(C)” may beset by the processor 210, by the user using any of the input devices242, or via commands received with the communication interface 230.

As examples, the margin for an application may be within 10% of thecontrol temperature T_(C) in one case, 5% of the control temperatureT_(C) in another case, 1% of the control temperature T_(C) in anothercase, etc. Therefore, as the margin may differ for different cases, thespecific margins given as examples above do not limit any examples ofthe disclosure.

When the heating system 100 monitors the sensors 120 periodically, thetemperature of the workpiece 130 may be at a temperature that is belowor above the control temperature T_(C). The monitoring period mayadjustable in some examples of the disclosure, while other examples ofthe disclosure may have a fixed monitoring period. The monitoring periodused may be variable in some examples of the disclosure while otherexamples of the disclosure may have a fixed monitoring period. That is,the monitoring period may change while monitoring the workpiece 130 orthe monitoring period may remain the same for a first workpiece 130 butmay be changed for a second workpiece 130. The monitoring period may betimed via a software timer in, for example, the operating system 222 orthe applications 224, or a hardware timer that may be a part of, forexample, the control circuitry 105.

Some examples involve determining that the control temperature T_(C) isreached when the temperature is within a temperature range. Thetemperature range may be fixed or variable depending on variousparameters such as, for example, the interval at which the temperatureof the workpiece is determined, the characteristics of the workpiece,etc.

In block 316, the control circuitry 105 disables the heating device 110to stop heating the workpiece 130 when the highest temperature T_(H)from any of the various sensors 120 indicates that the workpiece 130 hasreached the control temperature T_(C) or is at substantially the controltemperature T_(C).

In block 318, the control circuitry 105 monitors the continuing rise inovershoot temperature of the workpiece 130 based on the outputs of thesensors 120. Once the outputs of the sensors 120 indicate that thetemperature of the workpiece 130 has peaked, the temperature overshoot,which is the difference in temperature from the control temperatureT_(C) to the peak temperature, and the overshoot time, which is the timeperiod from when the heating device 110 is disabled to the workpiece 130reaching its peak temperature, are determined.

In block 320, a temperature ramp rate is determined by, for example, theprocessor 210 of the control circuitry 105 based on the temperatureovershoot and/or the overshoot time for use in heating the workpiece 130to the target temperature T_(T). The temperature ramp rate may be alinear ramp or a non-linear ramp. An example of a linear ramp may be,for example, increasing the control temperature T_(C) for the workpiece130 by a constant temperature amount per unit time until the targettemperature T_(T) is reached without overshooting beyond an acceptablemargin. The control temperature T_(C) may be increased, for example,periodically.

In some other examples, the control circuitry 105 controls thetemperature of the heating device 110 periodically such that thetemperature of the workpiece reaches substantially the targettemperature T_(T) without overshooting beyond an acceptable margin.“Substantially the target temperature T_(T)” may be a temperature withina margin to the target temperature T_(T) that may be pre-determined fora given usage. The margin may depend on various parameters, such as, forexample, the type of metal being heated, the type of heating device 110,etc. Accordingly, “substantially the target temperature T_(T)” may beset by the processor 210, by the user using any of the input devices242, or via commands received with the communication interface 230.

As examples, the margin for an application may be within 5% of thetarget temperature T_(T) in one case, 2% of the target temperature T_(T)in another case, 1% of the target temperature T_(T) in another case,etc. Therefore, as the margin may differ for different cases, thespecific margins given as examples above do not limit any examples ofthe disclosure.

The heating period used may be variable in some examples of thedisclosure while other examples of the disclosure may have a fixedperiod. That is, the heating period may change while heating theworkpiece 130 or the heating period may remain the same for a firstworkpiece 130 but may be changed for a second workpiece 130. The heatingperiod may be timed via a software timer in, for example, the operatingsystem 222 or the applications 224, or a hardware timer that may be apart of, for example, the control circuitry 105.

A single timer may be used for monitoring the temperature of theworkpiece 130 and for using the temperature ramp rate in heating theworkpiece 130, or independent timers may be used. The workpiece 130 maybe heated to an interim temperature T_(I) that is raised, for example,periodically based on the temperature ramp rate.

In block 322, the control circuitry 105 enables the heating device 110to heat the workpiece 130 to the target temperature T_(T) using thetemperature ramp rate. An example of the disclosure may increase atarget temperature of the workpiece 130 to an interim temperature T_(I)periodically until the interim temperature T_(I) equals the targettemperature T_(T). Accordingly, the heating device 110 can heat theworkpiece 130 according to the increasing interim temperature T_(I)until the target temperature T_(T) is reached.

In block 324, when the workpiece 130 reaches the target temperatureT_(T), or reaches substantially the target temperature T_(T), theheating device 110 is disabled.

While an example flow diagram is shown in FIG. 3 for illustrativepurposes, it should be understood that various other flow diagrams mayalso describe other examples of the disclosure. For example, in anotherexample of the disclosure, the blocks 306 and 308 may happen serially ineither order rather than in parallel as shown in FIG. 3.

FIG. 4 shows a detailed flow diagram representative of example machinereadable instructions 300, which may be executed by the example controlcircuitry 105, 200 of FIGS. 1 and/or 2 to implement the example heatingsystem of FIG. 1. The example instructions 400 may be performed toimplement block 312 of FIG. 3 to set the control temperature T_(C).

In block 402, the comparison of the target temperature T_(T) to thecurrent highest temperature T_(H) performed by the processor 210 isused. In block 404, in an example algorithm in the application 224executed by the processor 210, when the difference between the targettemperature T_(T) and the current highest temperature T_(H) is largerthan a threshold value (T_(R)), the control temperature T_(C) is set to:

T _(C) =T _(H) +m*(T _(R) −T _(H))  (Equation 1)

where ‘m’ is less than or equal to 1 and greater than or equal to 0.

Some examples of the disclosure may set ‘m’ to be in the range of, forexample, substantially 0.15 to substantially 0.75. An example of thedisclosure may set ‘m’ to, for example, substantially 0.25. Furthermore,some examples of the disclosure may set the threshold value (T_(R)) tobe in the range of, for example, substantially 10° C. to substantially50° C. An example of the disclosure may set the threshold value (T_(R))to, for example, substantially 25° C.

In an example algorithm, when the difference between the targettemperature T_(T) and the current highest temperature T_(H) is less thanor equal to the threshold value (TH1), the control temperature T_(C) isset by the processor 210 to the target temperature T_(T):

T _(C) =T _(T)  (Equation 2)

Accordingly, in some examples, the heating system 100 is configured tocontrol the heating device 110 based on the received target temperature(T_(T)), the temperature ramp rate, and feedback based on the outputs ofthe sensors 120.

FIG. 5 shows a flow diagram representative of example machine readableinstructions 500, which may be executed by the example control circuitry105, 200 of FIGS. 1 and/or 2 to implement the example heating system 100of FIG. 1. For example, the instructions 500, which may be in anapplication 224, may be executed by the processor 210 to control theheating device 110 to heat a workpiece 130 to a target temperature. Aninduction heating device is used as an example for the heating device110, and it should be understood that various examples of the disclosuremay use any type of heating device appropriate for a purpose such as,for example, welding.

In block 502, a start request for heating is received. In block 504, theheating device 110, for example, an induction heating device, isenabled. In block 506, a target temperature T_(T) to which the workpiece130 should be heated is received. The target temperature may be, forexample, entered or selected by a user via the input devices 242 orreceived from another electronic device wirelessly and/or by wiredcommunication via the communication interface 230. The workpiece 130 mayalso recognized by scanning an identification mark such as, for example,a bar code, with an input device 242, optically recognized by anapplication 224, etc., and then the target temperature looked up in, forexample, a look-up table in the memory 220.

In block 508, the control circuitry 105 receives, wirelessly and/or viawire conductors, outputs from one or more sensors 120, each configuredto monitor a temperatures at a location of the workpiece 130. Thetemperature monitoring may occur continuously or at some time interval.The control circuitry 105 selects a current temperature (T_(S)) for theworkpiece 130 monitored via the sensors 120. For example, the controlcircuitry 105 may receive a selection of one or more of the sensors 120(e.g., via the I/O module 240, the input devices 242) as a controlsensor for characterization of the workpiece and/or control of heating.In some examples, the control circuitry 105 selects the currenttemperature (T_(S)) as the highest observed temperature (e.g., thehighest temperature T_(H) of FIG. 3).

In block 510, the target temperature T_(T) is compared to the selectedcurrent temperature T_(S). Depending on the result of the comparison,the control temperature T_(C) is set in block 512. Block 512 may beimplemented using a process such as the process of FIG. 4, using theselected current temperature instead of the highest monitoredtemperature T_(H).

In block 514, the heating device 110 heats the workpiece 130 to thecontrol temperature T_(C), or to substantially the control temperatureT_(C) as allowed by the heating system 100. “Substantially the controltemperature T_(C)” may be a temperature within a pre-determined marginto the temperature T_(C) that may be pre-determined for a given usage.The pre-determined margin may depend on various parameters, such as, forexample, the type of metal being heated, the type of heating device 110,etc. Accordingly, “substantially the control temperature T_(C)” may beset by the processor 210, by the user using any of the input devices242, or via commands received with the communication interface 230.

As examples, the margin for an application may be within 10% of thecontrol temperature T_(C) in one case, 5% of the control temperatureT_(C) in another case, 1% of the control temperature T_(C) in anothercase, etc. Therefore, as the margin may differ for different cases, thespecific margins given as examples above do not limit any examples ofthe disclosure.

When the heating system 100 monitors the sensors 120 periodically, thetemperature of the workpiece 130 may be at a temperature that is belowor above the control temperature T_(C). The monitoring period mayadjustable in some examples of the disclosure, while other examples ofthe disclosure may have a fixed monitoring period. The monitoring periodused may be variable in some examples of the disclosure while otherexamples of the disclosure may have a fixed monitoring period. That is,the monitoring period may change while monitoring the workpiece 130 orthe monitoring period may remain the same for a first workpiece 130 butmay be changed for a second workpiece 130. The monitoring period may betimed via a software timer in, for example, the operating system 222 orthe applications 224, or a hardware timer that may be a part of, forexample, the control circuitry 105.

Some examples involve determining that the control temperature T_(C) isreached when the temperature is within a temperature range. Thetemperature range may be fixed or variable depending on variousparameters such as, for example, the interval at which the temperatureof the workpiece is determined, the characteristics of the workpiece,etc.

In block 516, the control circuitry 105 disables the heating device 110to stop heating the workpiece 130 when the highest temperature selectedcurrent temperature T_(S) from any of the various sensors 120 indicatesthat the workpiece 130 has reached the control temperature T_(C) or isat substantially the control temperature T_(C).

In block 518, the control circuitry 105 monitors the continuing rise inovershoot temperature of the workpiece 130 based on the outputs of thesensors 120. Once the outputs of the sensors 120 indicate that thetemperature of the workpiece 130 has peaked, the temperature overshoot,which is the difference in temperature from the control temperatureT_(C) to the peak temperature, and the overshoot time, which is the timeperiod from when the heating device 110 is disabled to the workpiece 130reaching its peak temperature, are determined.

In block 520, a temperature ramp rate is determined by, for example, theprocessor 210 of the control circuitry 105 based on the temperatureovershoot and/or the overshoot time for use in heating the workpiece 130to the target temperature T_(T). The temperature ramp rate may be alinear ramp or a non-linear ramp. An example of a linear ramp may be,for example, increasing the control temperature T_(C) for the workpiece130 by a constant temperature amount per unit time until the targettemperature T_(T) is reached without overshooting beyond an acceptablemargin. The control temperature T_(C) may be increased, for example,periodically.

In some other examples, the control circuitry 105 controls thetemperature of the heating device 110 periodically such that thetemperature of the workpiece reaches substantially the targettemperature T_(T) without overshooting beyond an acceptable margin.“Substantially the target temperature T_(T)” may be a temperature withina margin to the target temperature T_(T) that may be pre-determined fora given usage. The margin may depend on various parameters, such as, forexample, the type of metal being heated, the type of heating device 110,etc. Accordingly, “substantially the target temperature T_(T)” may beset by the processor 210, by the user using any of the input devices242, or via commands received with the communication interface 230.

As examples, the margin for an application may be within 5% of thetarget temperature T_(T) in one case, 2% of the target temperature T_(T)in another case, 1% of the target temperature T_(T) in another case,etc. Therefore, as the margin may differ for different cases, thespecific margins given as examples above do not limit any examples ofthe disclosure.

The heating period used may be variable in some examples of thedisclosure while other examples of the disclosure may have a fixedperiod. That is, the heating period may change while heating theworkpiece 130 or the heating period may remain the same for a firstworkpiece 130 but may be changed for a second workpiece 130. The heatingperiod may be timed via a software timer in, for example, the operatingsystem 222 or the applications 224, or a hardware timer that may be apart of, for example, the control circuitry 105.

A single timer may be used for monitoring the temperature of theworkpiece 130 and for using the temperature ramp rate in heating theworkpiece 130, or independent timers may be used. The workpiece 130 maybe heated to an interim temperature T_(I) that is raised, for example,periodically based on the temperature ramp rate.

In block 522, the control circuitry 105 enables the heating device 110to heat the workpiece 130 to the target temperature T_(T) using thetemperature ramp rate. An example of the disclosure may increase atarget temperature of the workpiece 130 to an interim temperature T_(I)periodically until the interim temperature T_(I) equals the targettemperature T_(T). Accordingly, the heating device 110 can heat theworkpiece 130 according to the increasing interim temperature T_(I)until the target temperature T_(T) is reached.

In block 524, during heating to the target temperature T_(T) using thetemperature ramp rate, the control circuitry 105 determines whether thecurrent selected temperature T_(S) decreases, which can indicate adecoupling of the selected control sensor 120 from the workpiece. Ifthere is a decrease in the selected current temperature T_(S) (block524), control returns to block 502 to restart the characterizationprocess using one or more different sensors as the selected currenttemperature T_(S). For example, a user may select a different set of oneor more sensors, and/or the one or more sensors may be automaticallyselected.

If there is not a decrease in the selected current temperature TS (block524), in block 526 the control circuitry 105 determines whether theselected current temperature T_(S) is greater than or equal to thetarget temperature T_(T). If the selected current temperature T_(S) isless than the target temperature T_(T) (block 526), control returns toblock 522 to continue to controlling the heating device 110.

When the selected current temperature T_(S) is greater than or equal tothe target temperature T_(T) (block 526), in block 528, the heatingdevice 110 is disabled.

While an example flow diagram is shown in FIG. 5 for illustrativepurposes, it should be understood that various other flow diagrams mayalso describe other examples of the disclosure. For example, in anotherexample of the disclosure, the blocks 506 and 508 may happen serially ineither order rather than in parallel as shown in FIG. 5.

While the disclosure has described various examples with respect towelding, it should be understood that the disclosure need not be solimited. Rather, the disclosure should be understood to apply to othersituations where an item needs to be heated or pre-heated.

Disclosed example systems for controlling heating of a workpiece includean interface configured to receive a target temperature (T_(T)) for theworkpiece, a processor, and a control system. The processor isconfigured to: select a current temperature (T_(S)) for the workpiecebased on monitoring one or more temperature sensors; and set a controltemperature (T_(C)) based on the received target temperature and theselected current temperature (T_(S)). The control system is configuredto control heating of the workpiece via a heating device until theworkpiece reaches the control temperature (T_(C)) as measured by atleast one of the one or more temperature sensors, and control theheating device to stop heating the workpiece in response to theworkpiece reaching the control temperature (T_(C)). The processor isfurther configured to characterize a temperature ramp rate based on ameasured temperature overshoot at the workpiece after turning off theheating device, and the control system is configured to control heatingof the workpiece to the received target temperature (T_(T)) bycontrolling the heating device based on the temperature ramp rate.

In some example systems, the processor is configured to set the controltemperature (T_(C)) to a temperature between the selected currenttemperature and the received target temperature (T_(T)). In some examplesystems, the processor is configured to select the current temperaturefor the workpiece based on a selection of at least one of the one ormore temperature sensors via the interface.

In some example systems, the processor is configured to: update thecharacterization of the temperature ramp rate in response to a change inthe selected current temperature or a change in the one or moretemperature sensors. In some example systems, the heating device isconfigured to heat the workpiece using induction. Some example systemsinclude a communication device configured to receive the targettemperature (T_(T)) via one or more of user interface, wiredcommunication from another device, and wireless communication fromanother device.

In some example systems, the processor is configured to perform one orboth of: monitor the outputs of the one or more temperature sensors atan expiration of a first time timer, and control updating an interimtemperature (T_(I)) based on the temperature ramp rate at an expirationof a second timer, wherein the control system is configured to heat theworkpiece to the interim temperature (T_(I)). In some example systems,the control system is configured to control the heating device based onthe received target temperature (T_(T)), the temperature ramp rate, andfeedback based on the outputs of the one or more temperature sensors.

In some example systems, the processor is configured to output an alarmor alert in response to detecting at least a threshold reduction in theselected current temperature while the heating device is heating theworkpiece. In some example systems, the processor is configured toselect the current temperature for the workpiece as a highesttemperature measured by the one or more temperature sensors. In someexample systems, the one or more temperature sensors include at leastone of an armored temperature sensing device, a spot-welded temperaturesensing device, a thermocouple, or an infrared temperature sensor.

The present methods and systems may be realized in hardware, software,and/or a combination of hardware and software. The present methodsand/or systems may be realized in a centralized fashion in at least onecomputing system, or in a distributed fashion where different elementsare spread across several interconnected computing systems. Any kind ofcomputing system or other apparatus adapted for carrying out the methodsdescribed herein is suited. A typical combination of hardware andsoftware may include a general-purpose computing system with a programor other code that, when being loaded and executed, controls thecomputing system such that it carries out the methods described herein.Another typical implementation may comprise one or more applicationspecific integrated circuit or chip. Some implementations may comprise anon-transitory machine-readable (e.g., computer readable) medium (e.g.,FLASH memory, optical disk, magnetic storage disk, or the like) havingstored thereon one or more lines of code executable by a machine,thereby causing the machine to perform processes as described herein. Asused herein, the term “non-transitory machine-readable medium” isdefined to include all types of machine readable storage media and toexclude propagating signals.

As utilized herein the terms “circuits” and “circuitry” refer tophysical electronic components (i.e. hardware) and any software and/orfirmware (“code”) which may configure the hardware, be executed by thehardware, and or otherwise be associated with the hardware. As usedherein, for example, a particular processor and memory may comprise afirst “circuit” when executing a first one or more lines of code and maycomprise a second “circuit” when executing a second one or more lines ofcode. As utilized herein, the term “exemplary” means serving as anon-limiting example, instance, or illustration. As utilized herein, theterms “e.g.” and “for example” set off lists of one or more non-limitingexamples, instances, or illustrations. As utilized herein, circuitry is“operable” to perform a function whenever the circuitry comprises thenecessary hardware and code (if any is necessary) to perform thefunction, regardless of whether performance of the function is disabledor not enabled (e.g., by a user-configurable setting, factory trim,etc.).

As utilized herein, “and/or” means any one or more of the items in thelist joined by “and/or.” As an example, “x and/or y” means any elementof the three-element set {(x), (y), (x, y)}. In other words, “x and/ory” means “one or both of x and y.” As another example, “x, y, and/or z”means any element of the seven-element set {(x), (y), (z), (x, y), (x,z), (y, z), (x, y, z)}. In other words, “x, y and/or z” means “one ormore of x, y and z.” As utilized herein, “one of x or y” or “one of xand y” is equivalent to any element of the set {(x), (y)}.

As utilized herein, the term “exemplary” means serving as a non-limitingexample, instance, or illustration. As utilized herein, the terms “e.g.”and “for example” set off lists of one or more non-limiting examples,instances, or illustrations. As utilized herein, circuitry is “operable”to perform a function whenever the circuitry comprises the necessaryhardware and code (if any is necessary) to perform the function,regardless of whether performance of the function is disabled or notenabled (e.g., by a user-configurable setting, factory trim, etc.).

While the present method and/or system has been described with referenceto certain examples and/or aspects, it will be understood by thoseskilled in the art that various changes may be made and equivalents maybe substituted without departing from the scope of the present methodand/or system. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the presentdisclosure without departing from its scope. Therefore, the presentmethod and/or system are not limited to the particular examplesdisclosed. Instead, the present method and/or system will include allimplementations falling within the scope of the appended claims, bothliterally and under the doctrine of equivalents.

What are claimed:
 1. A system for controlling heating of a workpiece,comprising: an interface configured to receive a target temperature(T_(T)) for the workpiece; a processor configured to: select a currenttemperature (T_(S)) for the workpiece based on monitoring one or moretemperature sensors; and set a control temperature (T_(C)) based on thereceived target temperature and the selected current temperature(T_(S)); and a control system configured to: control heating of theworkpiece via a heating device until the workpiece reaches the controltemperature (T_(C)) as measured by at least one of the one or moretemperature sensors, and control the heating device to stop heating theworkpiece in response to the workpiece reaching the control temperature(T_(C)); wherein: the processor is configured to characterize atemperature ramp rate based on a measured temperature overshoot at theworkpiece after turning off the heating device; and the control systemis configured to control heating of the workpiece to the received targettemperature (T_(T)) by controlling the heating device based on thetemperature ramp rate.
 2. The system of claim 1, wherein the processoris configured to set the control temperature (T_(C)) to a temperaturebetween the selected current temperature and the received targettemperature (T_(T)).
 3. The system of claim 1, wherein the processor isconfigured to select the current temperature for the workpiece based ona selection of at least one of the one or more temperature sensors viathe interface.
 4. The system of claim 1, wherein the processor isconfigured to: update the characterization of the temperature ramp ratein response to a change in the selected current temperature or a changein the one or more temperature sensors.
 5. The system of claim 1,wherein the heating device is configured to heat the workpiece usinginduction.
 6. The system of claim 1, comprising a communication deviceconfigured to receive the target temperature (T_(T)) via one or more ofuser interface, wired communication from another device, and wirelesscommunication from another device.
 7. The system of claim 1, wherein theprocessor is configured to perform one or both of: monitor the outputsof the one or more temperature sensors at an expiration of a first timetimer, and control updating an interim temperature (T_(I)) based on thetemperature ramp rate at an expiration of a second timer, wherein thecontrol system is configured to heat the workpiece to the interimtemperature (T_(I)).
 8. The system of claim 1, wherein the controlsystem is configured to control the heating device based on the receivedtarget temperature (T_(T)), the temperature ramp rate, and feedbackbased on the outputs of the one or more temperature sensors.
 9. Thesystem of claim 1, wherein the processor is configured to output analarm or alert in response to detecting at least a threshold reductionin the selected current temperature while the heating device is heatingthe workpiece.
 10. The system of claim 1, wherein the processor isconfigured to select the current temperature for the workpiece as ahighest temperature measured by the one or more temperature sensors. 11.The system of claim 1, wherein the one or more temperature sensorscomprise at least one of an armored temperature sensing device, aspot-welded temperature sensing device, a thermocouple, or an infraredtemperature sensor.